1. Field of the Invention
The invention relates to the construction method and the geometry for the pressure bulkhead of a fuselage, which seals a spatial area therein in a pressure-tight manner.
2. Discussion of Background Information
With larger transport aircraft, the fuselage for passengers and freight is stressed by the cabin pressure. In the area of the landing gear, only the cabin area is under pressure, such that the shaft for extending and retracting the landing gear is exposed to ambient pressure. This pressure difference is absorbed by a horizontal 1 and a vertical 2 bulkhead (see FIGS. 1 and 2), which as a rule are embodied in each case in a flat manner. The horizontal bulkhead is located directly under the floor of the cabin and is connected to the vertical bulkhead that separates the landing gear area from the freight area.
In the metal construction method, it is usual to embody the bulkheads from reinforced flat plates. In an alternative construction method, the pressure bulkhead, typically the horizontal bulkhead, comprises a lining-up of several single-curved pans that are shaped from metal sheets. Both construction methods are known and are used with transport aircraft. The size of the semi-finished products used, either sheets or plates, and the production methods set the limits for an integral construction method. A reinforced plate can be milled from one piece, whereas pan sheets have to be shaped individually and then joined with rivets or bolts together with reinforcing elements to form the bulkhead. For very large components it can be necessary for reasons of cost, semi-finished products, or other reasons related to machine processing to design a differential construction method that provides joints of the components with rivet and bolt connections.
In aircraft construction, the aluminum alloys are being more and more replaced by carbon fiber composite materials. In this manner even lighter structures can be designed, which can be produced at least at no additional cost compared to aluminum. Fibrous composite construction methods render possible highly integral large structural components that are not possible in metal in this manner. Thus, the costs of the joining technology are saved and compensates in part for the higher price for semi-finished product, material and production method.
With the introduction of carbon fibrous composite materials in lieu of aluminum, new, material-adapted solutions for pressure bulkheads must be developed in aircraft construction. The production of reinforcement profiles in fiber composite technology is cost-intensive and cannot compete with conventional metal construction methods. Surfaces with different thicknesses and local reinforcements, as well as curved surfaces, can be produced easily and with cost advantages compared to aluminum.